Jesus made it seem easy – but he wasn’t dealing with a rapidly changing climate! In this post I will discuss a project on optimizing irrigation efficiency in the Coonawarra region. Located 4 hours southeast of Adelaide, Coonawarra is primarily known for producing quality Cabernet sauvignon, but it has much more to offer than just cab (as I quickly discovered by sneaking in a few tastings after field work).
Spatial variability is inherent in vineyards, which can be attributed to differences in soil type, variety, rootstock, disease, etc. This means that the vines won’t all grow the same or be equally healthy across any given vineyard. Technology that reveals vineyard variability can allow growers to allocate their resources more efficiently by adjusting inputs like water and nutrients. Additionally, technology that provides continuous data on the vines’ physiological status is useful in making well-timed irrigation decisions. The goal of this project is to characterize the spatial variability and provide growers with continuous information. Such monitoring capabilities are incredibly valuable to any viticulturist, especially given the increased likelihood of severe droughts and extreme temperature events due to climate change.
We visited the site twice in February – the first time we installed infrared canopy temperature sensors (prototypes built from scratch by Joe Hu, one of Vinay’s masters students) and the second time we went to troubleshoot the sensors and take physiological measurements. Simultaneously, a plane flew overhead capturing NDVI (normalized differential vegetation index, essentially a measure of “greenness” that can indicate vine health) and thermal images of entire vineyard blocks. The basic idea is that the infrared canopy temperature sensors will provide similar data to that of the plane, except it will be continuous (recording temperature every 10 minutes) and less expensive than flying a plane. Also, the plane gave us an initial idea of each vineyard’s variability, so we installed some canopy temperature sensors in areas of interest where the vines looked particularly stressed. We also performed Vinay’s classic suite of field measurements: gas exchange, pre-dawn and midday water potential, chlorophyll content, and FLIR thermal imaging. We are now completely drowning in data! But it’s great, we are learning so much about what’s going on at a macro and micro level in Coonawarra.
Aside from the Coonawarra project, we are very busy. We harvested the Sauvignon blanc from Riverland (that in-canopy mist experiment was discussed in my prior post) and made the wine. Vinay has also gotten me started on my own small experiment in which I will compare how certain varieties respond to high temperatures in different ways. This involves a lot of stem water potentials and gas exchange. I was initially intimidated by the LICOR (gas exchange machine) with its millions of buttons and settings, but it is quickly becoming my best friend in the field. I have to forget that it is more expensive than a Ferrari, though, or I get all nervous about touching it.
In other news, the Adelaide Fringe Festival has just kicked off – this is the biggest arts festival in the southern hemisphere and apparently the second biggest in the world. I attended the opening parade and an acrobatics show so far, both were pretty cool. I’m going to try to go to as much of it as I can in between all the harvesting, winemaking, field measurements, and data analysis.
Oh, and spiders here are huge. And they’re all over my house, and I don’t know if I will ever be ok with it.
I hope I explained everything clearly in this post, but please let me know in the comments if you have any questions!